Aircraft include movable control surfaces for directional control in flight. Such control surfaces can include ailerons for roll control, elevators for pitch control, and rudders for yaw control.
Hydraulic drive systems with linear actuators have been used for control surfaces and other control surface systems. Servo valves are used in hydraulic actuators to regulate the flow of hydraulic fluid, which then affects the position of a piston in the hydraulic actuator, and therefore the force of the actuator.
The servo valve position may be controlled by the magnetic flux generated by one or more coils, and therefore may be referred to as an Electrohydraulic Servo Valve (EHSV) or a Direct Drive Valve (DDV). A failure which causes an erroneous level of current to flow through the coil may cause the actuator to move to a position or output a force that is not consistent with the expected output of the control system. Such a failure could cause the aircraft to deviate from a controlled course and/or cause structural damage to components of the aircraft. Accordingly, systems and methods to control servo systems which, in turn, manage control surfaces may find utility.